Brushing machine



4 Sheets-Sheet l Attorni Filed June 28, 1960 Nov. 20, 1962 E. R. BLEKEBRUSHING MACHINE 4 Sheets-Sheet 2 Filed June 28, 1960 Nov. 20, 1962 E.R. BLEKE BRUSHING MACHINE 4 Sheets-Sheet 3 fin 4917470,". E7019 REAP/Xe,

by J

Filed June 28, 1960 Nov. 20, 1962 E. R. BLEKE 3,064,290

BRUSHING MACHINE Filed June 28, 1960 4 Sheets-Sheet 4 A 880 r-ney UnitedStates Patent )fifice 3,@54,Z9ll Patented Nov. 20, 1952 3,064,296BRUSHING MACHINE Ellis R. Blelre, Midland Park, NJ, assignor to GeneralElectric Company, a corporation of New York Filed June 28, 1960, Ser.No. 39,248 7 Claims. (Ci. -21) My invention relates to automaticbrushing and bufiing machines and more particularly to an improvedmachine for brushing newly formed gears.

In the production of gears for use in gear motors and the like, it iscustomary to perform a brushing operation on the gears afterthey havebeen formed in the gear cutting machine. The brushing operation isdesirable in order to remove burrs, sharp corners and otherimperfections from the gears. The brushing operation traditionally hasbeen done manually by an operator placing a gear on a loose fittingshoulder mandrel and then holding the gear against a revolving brush.The brush as it operates against the gear rotates the gear by its actionon the teeth so that the entire top side of the gear exposed to thebrush is contacted by the bristles. When the top side of the gear isbrushed sufliciently, the operator removes the gear from the brush,turns it over on the mandrel and repeats the brushing on the secondside. This is obviously a rather time consuming and costly process dueto the high labor content involved.

In order to reduce the cost of the operation, and also to get a uniformbrushing action on each gear, it would be desirable if the brushingoperation could be performed on an automatic machine. Such a machineshould be adjustable so as to provide for varying size gears and also toprovide for diflerent brush pressures on difierent gears, i.e.,different brush loads. Also, since the brushes wear considerably duringuse, it would be necessary that the machine be so arranged that the wearon the brushes will not adversely affect the brushing action. Further,the machine should be so constructed and arranged that it could be runby a relatively unskilled operator with little set-up or adjustment timebeing required.

Accordingly, it is a primary object of my invention to provide a new andimproved brushing or bufling machine which is especially useful forbrushing newly formed gears.

Another object of my invention is to provide an improved brushingmachine having indicating means for showing the brush pressure or loadand means for adjusting the brush position so as to obtain the desiredload.

A further object of my invention is to provide an improved brushingmachine in which the brush speed may be readily varied to provide thesame peripheral speed of the bristles regardless of the condition ofbrush wear.

A still further object of my invention is to provide an improvedautomatic brushing machine in which no manual actions are required afterthe brush position and speed are set other than the loading andunloading of the machine.

In carrying out my invention in one form thereof, I provide a gearbrushing machine having at least one rotatable brush and an adjustablespeed drive mechanism for driving the brush. An indexing table isincluded having a plurality of spindles for mounting the gears to bebrushed, and means are provided for moving the table in a step by stepfashion to bring the spindles progressively in front of the brush.Thereby the gears are progressively brought into contact with the brushfor the brushing action, and the desired peripheral speed of the brushfor the correct brushing action is obtained regardless of the conditionof brush wear by the adjustment of the drive mechanism.

In order that a predetermined brush pressure may be maintained on thegears, the machine includes means whereby the brush and the indexingmeans may be moved relatively toward and away from each other. Thus, themachine may be adjusted for different sizes of gears and also tocompensate for brush wear. By a further aspect of my invention, themachine includes means whereby the pressure or load on the brush may bemeasured thereby to insure that the proper brushing action is obtained.This measuring means comprises an ammeter which measures the inputcurrent to the drive motor of the adjustable speed drive mechanism. Thiscurrent is determined by the load on the brush and thereby the ammeter,in effect, indicates the magnitude of the brushing action taking place.The desired brushing action in each instance may thereby be obtained byadjusting the brush position until the input current corresponding tothe desired brushing action appears on the amrneter.

The subject matter which I regard as my invention is particularlypointed out and distinctly claimed in the concluding portion of thisspecification. My invention, however, both as to organization and methodof operation together with further objects and advantages thereof maybest be understood by reference to the following description taken inconjunction with the accompanying drawings in which:

PEG. 1 is a perspective view from the front of one embodiment of my gearbrushing machine;

FIG. 2 is a top view of the machine, with certain parts removed andpartially broken away so as to show details of the indexing table and ofthe brush and gear contact;

PEG. 3 is a front elevation view showing the drive mechanism for one ofthe brushes, the view being partially broken away to illustrate innerdetails of the drive mechanism;

FIG. 4 is a top view of the indexing table, partially broken away toshow the indexing drive and detent means for the table;

PEG. 5 is a sectional view of the indexing table and its drive taken onthe line 5--5 of FIG. 4;

FIG. 6 is a sectional view taken on the line 6-6 of 4 1G. 3 showing oneof the gear mounting spindles carried by the indexing table;

FIG. 7 is a perspective view of a backing member disposed over theindexing table;

FIG. 8 is a fragmentary view showing the gear brushing action occurringat one of the brushes; and

FIG. 9 is a schematic circuit diagram illustrating the electricalconnections for energizing the drive motor for one of the drivemechanisms and the timer for controlling the indexing table.

Referring now to FIG. 1, I have shown therein a preferred embodiment ofmy new and improved gear brushing machine 1. This machine includes apair of brushes 2 and 3 which are arranged for rotation adjacent to anindexing table or carrier 4. The brushes 2 and 3 are driven respectivelyby mechanically adjustable, variable speed drive mechanisms 5 and 6 andthey rotate in opposite directions with regard to the indexing table.Specifically, the brush 2 is driven in a counterclockwise direction asindicated by the arrow 7 so that it moves downwardly past the indexingtable, while the brush 3 is driven in a clockwise direction as indicatedby the arrow 8 so that it moves upwardly past the indexing table.

As shown in FIGS. 1, 2 and 4, the indexing table 4 is provided with aplurality of rotatable spindles 9. In particular, the table is providedwith six of these spindles which are supported thereon in a generallycircular pattern by means of ball bearing assemblies 9a (PEG. 6). Thespindles 9 are arranged to receive the gears 10 to be brushed and aflange 11 is provided on each spindle immediately above its ball bearingmount 9a for supporting the gear once it is placed on the spindle.

The indexing table 4 is moved in a step by step fashion to bring thespindles 9 progressively in front of the brushes 2 and 3, this movementbeing in a clockwise direction in the illustrated machine. As eachspindle is brought in front of either brush 2 or brush 3, the gearmounted on it is brought into contact with the brush so that a brushingaction occurs. The gear mounted on any spindle is thus first brushed bythe brush 2, with the brush moving in the downward direction past it,and then is moved into contact with the brush 3, with brush 3 movingupwardly past it. The means for moving the table in this step by stepfashion will be explained hereinafter and it will be noted that thereare, in effect, six stations of the table corresponding to the sixspindles. In two of these stations, the gears 10 are being brushed bythe respective brushes whereas in the other four stations the gears maybe freely removed and replaced on the spindles. These other fourstations may, of course, be used for loading and unloading gears fromthe table.

It will be noted that the six spindles 9 are preferably staggeredslightly from the center lines which would place them exactlyequidistant from each other. This is done so that the gears mounted onany two spindles will not contact the brushes at the same portions oftheir respective widths. This off-centering gives greater brush life andprevents the brushes from wearing to a concave contour. It would, ofcourse; be difficult to bring the gears 10 into and out of contact withthe brushes if they were worn to a concave configuration.

Referring now to the drive for the brushes 2 and 3, it will beremembered that they are driven respectively by the adjustable speeddrive mechanisms and 6. Each of these mechanisms is provided with itsown drive motor as indicated at 12 and 13 respectively and they areidentical in construction and arrangement. Thus, only the mechanism 5will be described in detail herein. As shown in FIG. 3, the drivemechanism 5 comprises an adjustable speed belt and pulley driveconnecting the output shaft of the motor 12 (not shown) to an outputshaft 14 on which the brush 2 is mounted. The drive includes a pair ofadjustable pitch pulleys 15 and 16, the pulley 15 being mounted on themotor or drive shaft and the pulley 16 being mounted on the output shaft14. The pulleys 15 and 16 are connected together by means of a drivebelt 17 and the output speed of the mechanism, i.e., the speed of theshaft 14, is adjusted by changing the relative effective diameters ofthe pulleys 15 and 16.

The pulley 15 comprises the control pulley of the arrangement and itstwo halves may be adjusted relatively toward or away from each other bymeans of a mechanical linkage (not shown) which is controlled by amanually operated rotatable handle 18. Actually, the position of theright-hand pulley half is fixed on the shaft, and the left-hand half ismoved along the shaft when the handle 18 is turned. As the one half ofthe pulley 15 is moved toward or away from the other half, the effectivediameter of the pulley 15 is changed. Depending upon the direction thatthe effective diameter of the pulley 15 is changed, the belt 17 eitherslackens or pulls harder with regard to the pulley 16. The left-handhalf or section of the pulley 16 is fixedly mounted on the shaft 14 bythe collar 16a but the right-hand section is movable axially on theshaft, being biased toward the left-hand section by means of a coilspring 19. As the belt slackens or pulls harder against the pulley 16,depending upon the direction of adjustment of the pulley 15, the movablesection of the pulley 16 moves either toward or away from the fixedsection so as to vary the effective diameter of pulley 16. Inparticular, as the effective diameter of the pulley 15 is changed in onedirection, the effective diameter of the pulley 16 is changed in theother direction. If the effective diameter of the pulley 15 isincreased, the effective diameter of the pulley 16 is decreased, whereasif the effective diameter of the pulley 15 is decreased, that of theoutput pulley 16 is increased. Thus, as the adjusting crank is moved toits various posi tions, the speed of the output shaft 14 is changedrelative to that of the motor shaft so that the output speed isadjustable over a wide range. For example, in the illustrated machine atthe low speed adjustment of the crank 18 as indicated by the numeral 1on the scale 29 the output shaft will be driven at a speed of 525 r.p.m.assuming a motor speed of 1725 r.p.m., and at the high end adjustment asindicated by the numeral 9 on the scale 20 the output shaft will bedrive at 3675 rpm.

It will be understood that various types of mechanically adjustablevariable speed drives may be used to drive the brushes of my gearbrushing machine and, therefore, the mechanism 5 has not been describedherein in exhaustive detail. A preferred form of an adjustable speeddrive corresponding to the mechanism 5 is, however, described in detailand claimed in the copending application of Julius A. Kohn et al.,Serial Number 857,872, filed December 7, 1959, now Patent No. 3,009,363for (Variable Ratio Transmission Mechanism and assigned to the sameassignee as the present invention. Reference may be had to the aforesaidKohn application for a complete description of the control linkageutilized between the handle 18 and the control pulley 15 in theillustrated drive 5 and for other details of the mechanism.

Turning next to the indexing table 4, it is mounted on the base 21 ofthe machine by means of a base member 22 which is secured to the frameby bolts 23. The frame 22 carries a central pedestal 24 at the top ofwhich is mounted a ball bearing assembly 25 (see FIG. 5). The inner raceof the ball bearing assembly 25 is attached to the pedestal 24 and theouter race of the assembly carries a rotatable detent plate 26.Immediately above the detent plate 26 and carried by it is an actuatingplate 27 for the table 4 and disposed on top of the actuating plate 27is the table 4 itself. The detent plate 26, the actuating plate 27 andthe table 4 are all attached together into a unitary assembly by meansof a plurality of vertical bolts 28, with the entire assembly beingmounted for rotation by the ball bearing mount 25.

In order to rotate the table 4 in a step by step fashion, a pair of aircylinders 29 and 30 are provided in the machine (see FIGS. 1 and 4). Themovable piston of cylinder 29 drives a longitudinally movable dog 31which is arranged to engage suitable shoulders 32 provided on theactuating plate 27, While the piston of cylinder 30 controls a detentpin 33 which is arranged to engage recesses 34 provided in the detentplate 26. As shown in FIGS. 2 and 5, there are six of the shoulders 32provided on the plate 27 and six of the detent recesses 34 provided inthe plate 26.

Whenever the table 4 is in one of its stations with two spindlespositioned respectively in front of the gears 2 and 3, the pin 33 is inan extended position seated within a recess 34 as shown in FIG. 2. Atthe same time, the dog 31 is in an extended position engaging one of theshoulders 32. To move or index the table to the next station bringing anew gear into contact with the brush 2 and moving the previous gear infront of the brush 2 to contact with the brush 3, the detent pin 33 isfirst retracted by the cylinder 30 to its position shown in FIG. 4 sothat it clears the detent plate 26. Then the cylinder 29 retracts thedog 31 to its position shown in FIG. 4 moving the table to the nextposition. At this time, the cylinder 30 releases the pin 33 so that itengages the next recess 34 locking the table 4 in position, andthereafter the dog 31 is returned to its extended position by thecylinder 29 ready for the next movement of the table. It will be notedthat sloping surfaces 35 are provided on the actuating plate 27 betweenthe shoulders 32 so as to allow the dog 31 to ride backwardly from oneshoulder 32 to the next as it returns to its extended position.

To reiterate this sequence of actuation for the indexing table, it willbe understood that each time the table is to be indexed to the nextstation, the following sequence occurs. First, the pin 33 is retractedso as to release the table for movement, then the dog 31 draws the tableto the next position. The indexing pin then reseats in the next detentrecess locking the table in position, and the dog 31 returns outwardlyready for the next movement of the table.

The control of the air cylinders 29 and 3% to accomplish this indexingaction is effected by means of suitable electrically actuated valvingmeans which is controlled by means of a sequence timer 65. As shownschematically in FIG. 9, the timer 65 may be energized from one phase ofthe power supply for motor 12, and it may be connected to the valves forthe air cylinders in any suitable manner as also indicated schematicallyin FIG. 9. It will be understood that the particular form of timer andactuating means used with the indexing table is not essential to thisinvention and that other suitable means may be used to move the table ina step by step fashion to the various stations.

As the table 4 is moved in a step by step fashion, it, of course, bringsthe gears on the spindles '9 progressively in front of the brushes 2 and3. Since the brush 2 moves downwardly past the table, it does not tendto throw the gear off the spindle 9 in front of it, but rather, causesthe gear and the spindle to rotate together. In fact, the gear is seatedon the rotatable flange 11 of the spindle by the force of the brush asthis rotation occurs. The brush 3 does not, however, tend to force thegear downwardly onto the spindle flange 11 as does the brush 2. Rather,since the brush 3 moves upwardly past the table 4, it tends to lift thegear 10 off the spindle in front of it. It causes the gear in front ofit to rotate on a spindle 9 but at the same time provides an upwardforce which would lift the gear off the spindle if means were notprovided to prevent this. In order to retain the gear on the spindle infront of the upwardly moving brush 3, a backing member or plate 36 ispositioned over the indexing table. As shown in FIG. 5, this plate issupported by means of two stationary rods 37 and 38, the rod 37extending downwardly through the rotatable indexing table 4 into thestationary pedestal 24 and the rod 38 extending downvardly outside ofthe frame 22 to the base 21 of the machine. =It will be noted that theplate 36 is generally triangular in shape and that the supporting rods37 and 38 engage it at two of its corners. The third or unsupportedcorner of the plate lies directly in front of the brush 3 and as thetable indexes so as to carry a gear 16 from the brush 2 to the brush 3,the gear moves under the plate until it reaches the unsupported orright-hand corner as viewed at FIG. 1. When the gear reaches thiscorner, the table 4- then stops moving and the gear is in position to bebrushed by the brush 3.

Mounted on the bottom side of the plate 36 in front of the brush 3 is arotatable disc 39. The disc is carried by a stub shaft 39a journaled inthe plate 36 and when a gear is brought into position to be brushed bythe brush 3, the disc overlies the gear. Thus, as the brush 3 tends tolift the gear as it brushes it, the gear is engaged by the disc 39 andis thereby retained on the spindle. Thereby, during the brushing action,the gear is really rotated on the spindle by the brush but yet cannotfly off the spindle. The disc 39 rotates readily with the gear andspindle so that it does not interfere with the rotation of the gear,which rotation is necessary if all parts of the periphery of the gearare to be brushed. Sufficient clearance is provided between the disc andthe top of the spindles 9 so that the gear being brushed may be freelymoved from the brushing station upon the next indexing of the table justas it moved freely under the disc during the previous indexing.

To provide for brushing the gears of different sizes, and to compensatefor brush wear and to provide for setting the proper brush pressure onthe gears, the machine 1 includes means whereby the brushes 2 and 3 andthe table 4 may be moved relatively toward and away from each other. Inparticular, the drive mechanisms 5 and 6 for the brushes are mounted sothat they may be moved as units so as to move the brushes toward or awayfrom the table. The mounting for the drive units 5 and 6 is best shownin FIGS. 1 and 3. Referring to these figures, it will be seen that eachof the drive units is provided with a pair of front feet 40' and a pairof rear feet 41. These feet carry bolts 42; and 43 respectively whichextend through front and rear slots 44 and 45 in the base plate 21.Mounted on the bolts 42 and 43 on the under side of the base plate arecross members 46, these members being retained on the bolts by means ofsuitable nuts 47 and 48. With this arrangement, the drive mechanisms 5and 6 are free to slide on the base plate 21 with the 42 and 43 movingin the slots 44 and 45 so as to guide the direction of movement. It willbe noted that the slots 44 and 45 extend at an angle such that themovement of the drive units carries the brushes radially toward or awayfrom the indexing table.

A manually actuated screw is provided for moving each of the driveunits. Referring in particular to FIG. 1, it will be noted that theactuating means for the drive mechanism 6 are shown therein, and it willbe understood that generally this same arrangement is used with thedrive mechanism 5. As shown in FIG. 1, the actuating member for thedrive mechanism 6 comprises an elongated rod 49 which is threaded at itsouter end into the cross member 46 of the support for the drivemechanism 6. Outwardly from the member 46 the rod 49 is journaled in abearing 50 which is carried by a hanger 51 mounted on the bottom of thebase plate 21. The mounting of the rod 49 in the bearing 50 is such thatit may rotate freely with regard to the bearing 50 but does not moveaxially with regard thereto. At the outer end of the rod 49 a handwheel52 is provided whereby the rod may be turned for moving drive mechanism6. It will be understood that as the handwheel is turned, the rod 49rotates in the bearing 5%) and the threaded engagement between the outerend of the rod and the cross member 46 causes the drive mechanism 6 tomove in one direction or another depending upon the direction in whichthe handwheel is turned, thereby moving the brush 3 toward or away fromthe table. As mentioned above, a similar arrangement is provided formoving the drive mechanism 5 to adjust the brush 2 toward or away fromthe table 4, this arrangement being actuated by the handwheel 53.

For any particular type of gear, it is desirable that a particularbrushing pressure be maintained, in other words, that the brushes beloaded to a predetermined amount. In my improved machine, the desiredbrush pressure or load is readily obtained by adjusting brushes towardor away from the table 4. In particular, the handwheel 53 of the drive 5is turned so as to adjust the pressure of brush 2 on the gears coming infront of it, and the handwheel 52 is turned to adjust the pressure ofbrush 3 on the gears coming in front of it.

In order that the presure or load on the respective brushes may bereadily determined, I have included indicating means in my machine 1which will give a visual indication of that load. In particular, I haveconnected an ammeter in the energizing circuit for each of the drivemotors 12 and 13. The current drawn by the motors is, of course,proportional to the brush load and thereby the current shown on theammeters gives an indication of the brush load. Referring to FIG. 1, itwill be seen that the drive unit 5 has mounted thereon an ammeter 54 andthis meter measures the current in the motor 12. Likewise, the driveunit 6 has an ammeter 55 mounted thereon and this meter 55 measures thecurrent in the motor 13. When the machine is set up to brush anyparticular size and configuration of gear, the position of the brushesis adjusted until the proper brush pressure or load is obtained. Thisload, of course, draws a particular current to the motors 12 and 13 asindicated by the amrneters. Thereafter, the operator merely adjusts thehandwheels 52 and 53 to keep this same current flowing to the motors andthereby he is assured that the proper brushing pressure is being appliedto the gears.

In FIG. 9, I have shown in schematic form the connections for energizingthe motor 12. As there shown, the motor 12 is a three-phase inductionmotor and the ammeter 54- is connected in one phase of the supply. Itwill be understood that a single phase motor could be used to drive theadjustable speed drive unit and in that case the ammeter would beconnected serially in one of the two energizing leads. The sameconnection of the ammeter 55 is, of course, used for the motor 13 andtherefore it has not been illustrated herein. It will be noted that thetimer65 for the air cylinders of the indexing table is energized acrossone phase of the motor supply voltage and that the entire circuit iscontrolled by a start switch indicated at 56. Any suitable switch may beused and therefore no details will be shown herein. A similar switch 57(FIG. 1) is provided for the motor 13 of the drive unit 6.

Besides maintaining the proper brush pressure at all times, it is alsodesirable that the peripheral speed of the brushes past the gears bemaintained relatively constant for any given type of gear to be brushed.As the brushes wear down, it is, of course, necessary that therevolutions per minute of the brush carrying shafts be increased if theperipheral speed of the brushes is to be held constant. This isaccomplished by means of the adjustable speed drive mechanisms 5 and 6.As the brushes Wear down, the respective adjusting handles 18 and 58 ofthe mechanisms are gradually moved from their low speed position towardtheir high speed position thereby increasing the rotational speed of thebrushes to keep the same peripheral speed. It will be noted that withthe illustrated type of drive mechanisms, the speed variation iscontinuous rather than step by step as the handles are turned. Thus, nomatter what the condition of brush wear, the desired peripheral speed ofthe brushes may be maintained. Also, it will be noted that theadjustable speed drive mechanisms allow for the holding of diiferentperipheral speeds for diiferent types of gears. That is, a differentconstant speed may be held for one type of gear than for another type ofgear, where it is advantageous to do so.

To explain in further detail the operation of my improved gear brushingmachine, it will be understood that the indexing table 4 is movedcontinuously in a step by step fashion during the operation of themachine. As the table moves, the spindles 9 are continuously brought infront of the brushes 2 and 3 so that the gears mounted thereon arecontacted by the brushes and brushed thereby. The table moves in aclockwise direction and the operator continuously removes the gearsleaving the brush 3 and places on new rough gears for brushing. Theoperator maintains the correct brushing pressure at all times merely byadjusting the brush pressure so as to maintain a predetermined currenton the ammeters 54 and 55. The drive mechanisms 5 and 6 are, of course,moved as a whole by means of the handwheels 52 and 53 to acomplish thisresult. Also, in the event it is desirable to brush a different size ofgear, the handwheels 52 and 53 provide for adjustment of the brushes forcontacting the different sizes of gears. As the brushes wear down, theoperator adjusts the ratios of the drive mechanisrns 5 and 6 by means ofthe cranks 18 and 58 and thereby maintains the desired peripheral speedof the brushes. In the event a different peripheral speed is needed fora different type of gear, this is also readily obtained by adjusting theratios of the drive mechanisms.

It will be noted that during the brushing action the brush 2 moves thegears downwardly onto the flange of the spindle 9 in front of it so thatthe gears do not fly oif, while rotatable disc 39 of the backing member36 retains the gears on the spindle in front of the brush 3. Due to theangle at which the brushes contact the gears, they are rotated on thespindle 9 during brushing so that the brushes contact each tooth of thegears. The contact between the gears and the brushes is best shown inFIG. 8. The movement of the indexing table 4 is, of course, automatic ascontrolled by the timer 65 and thus the only task that the operator hasonce the machine is in operation is to unload the finished gears and puton rough gears. Of course, he will from time to time, adjust positionand ratio of the drive units so as to maintain the desired brush loadand peripheral brush speed but this may be readily done without takingthe machine out of operation and without any particular loss of brushingtime.

To obtain the proper brushing action, to remove sharp corners, burrs,etc., from the gears, it is desirable that an abrasive compound beapplied to the bristles of the brushes. In my improved machine, theabrasive is applied automatically to the brushes, the same type ofapplicator being used for each of the brushes. Referring particularly tothe applicator used with the brush 2, as shown in FIG. 1, the applicatorcomprises a reciprocating mechanism 59 which carries a hollow tube 60within which is positioned a bar of abrasive compound. The applicatorreciprocates approximately 14 strokes a minute and simultaneously feedsthe compound bar mounted within the tube 60 toward the brushes at a ratewhich is adjustable, for example, from .0015 inch to .015 inch perstroke. The applicator is driven by means of a gear motor 61 whichdrives a crank mechanism indicated at 62. The mechanism 62 is connectedto the applicator 59 so as to cause it to reciprocate back and forth asmentioned above. It will be understood that any suitable means may beused for applying the compound to the brushes and that the illustratedmechanism is intended only to be exemplary of such means.

While in accordance with the patent statutes I have described what atpresent is considered to be the preferred embodiment of my invention, itwill be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and it is, therefore, aimed in the appended claims to cover all suchvariations as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A brushing machine comprising a pair of rotatable brushes, a pair ofadjustable speed drive mechanisms each for driving one of said brushes,said drive mechanisms each including manually operable control means foradjusting the output speed thereof whereby a constant peripheral speedof said brushes may be maintained 'at varying conditions of brush wear,one of said brushes being driven in a clockwise direction and the otherof said brushes being driven in a counterclockwise direction, arotatable indexing table having a plurality of stations for mounting thearticles to be brushed, means for moving said table in a step by stepfashion to bring said stations progressively in front of said brushesand thereby bring said articles into contact with said brushes, meansfor moving said brushes separately toward and away from said indexingtable for independent adjustment of the pressure of each of said brushesagainst said articles, a separate electric motor for driving each ofsaid adjustable speed drive mechanisms and separate ammeters formeasuring input current to each of said motors thereby to indicate thepressure of each of said brushes against said gears.

2. A brushing machine comprising at least one rotatable brush, a carriermeans having a plurality of stations for mounting the articles to bebrushed, means for moving said carrier means to bring said stationsprogressively in front of each brush and thereby bring said articlesinto contact with each brush, and an adjustable speed drive mechanismfor driving each brush, whereby a constant peripheral speed of eachbrush may be maintained at varying conditions of brush wear, eachadjustable speed drive mechanism including a drive motor, an input shaftdriven by said drive motor, an output shaft carrying one brush, pulleyand belt means connecting said shafts, and means for adjusting the inputto output speed ratio of the belt and pulley means thereby to vary thespeed of the output shaft.

3. A gear brushing machine comprising a pair of rotatable brushespositioned at spaced apart locations, a rotatable indexing table havinga plurality of spindles for mounting the gears to be brushed, means formoving said table in a step by step fashion to bring said spindlesprogressively in front of said brushes and thereby to bring said gearsinto contact with said brushes, a separate adjustable speed drivemechanism for driving each of said brushes, with one of said brushesbeing driven upwardly past said table and the other of said brushesbeing driven downwardly past said table, manually operable control meansfor adjusting said drive mechanisms for maintaining a constantperipheral speed of said brushes at varying conditions of brush wear, abacking member mounted above said table in front of said upwardly movingbrush for holding said gears on said spindles as they are engaged bysaid upwardly moving brush, said backing member including a rotatabledisc arranged to engage said gears during brushing by said upwardlymoving brush whereby said gears are free to rotate during brushingthereby, and means for moving said brushes separately toward and awayfrom said indexing table for independent adjustment of the pressure ofsaid brushes against said gears.

4. A gear brushing machine comprising a pair of rotatable brushespositioned at spaced apart locations, a rotatable indexing table havinga plurality of spindles for mounting the gears to be brushed, means formoving said table in a step by step fashion to bring said spindlesprogressively in front of said brushes and thereby to bring said gearsinto contact wtih said brushes, said spindles being staggered slightlyfrom equi-distant positions on said table whereby the gears on differentspindles contact different areas on said brushes to avoid wearing saidbrushes to a concave contour, a pair of adjustable speed drivemechanisms each for driving one of said brushes, and said drivemechanisms each including manually operable means for adjusting theoutput speed thereof whereby a constant peripheral speed of said brushesmay be maintained at varying conditions of brush wear.

5. A gear brushing mechanism comprising a base, a rotatable tablemounted on said base and having a plurality of spindles for mounting thegears to be brushed, a pair of unitary adjustable speed drive mechanismsmovably mounted on said base at spaced apart locations adjacent toperiphery of said tables, each of said drive means including a drivemotor, an input shaft driven by said drive motor, an output shaft, andpulley and belt means connecting said shaft, and means for adjusting theinput to output speed ratio of the belt and pulley means whereby thespeed of said output shaft may be varied, a pair of brushes mountedrespectively on the output shafts of said drive mechanisms and locatedadjacent said table,

carrier means for moving said table to bring said spindles progressivelyin front of said brushes and thereby to bring said gears into contactwith said brushes, and manually operable means for moving said unitarydrive mechanisms separately toward and away from said indexing table forindependent adjustment of the pressure of said brushes against saidgears.

6. The mechanism of claim 5 wherein one of the brushes is drivenupwardly past the table and the other of said brushes is drivendownwardly past said table, and a rotatable disc is supported from saidbase in front of the upwardly moving brush for holding said gears onsaid spindles as they are engaged by the upwardly moving brush.

7. The mechanism of claim 6 wherein said spindles are staggered slightlyfrom equi-distant points along the periphery of said table thereby toprevent concave wearing of said brushes.

References Cited in the file of this patent UNITED STATES PATENTS1,853,078 Phelps et a1 Apr. 12, 1932 1,886,699 Larson Nov. 8, 19322,106,442 Stevens Ian. 25, 1938 2,177,898 Leguillon et a1 Oct. 31, 19392,671,913 Kirsch Mar. 16, 1954 2,881,570 Moore et a1 Apr. 14, 19592,893,253 Beerner July 7, 1959 2,928,112 Nelson Mar. 15, 1960 2,951,254Cole et al Sept. 6, 1960

